In the present digital world, Information and Communication Technology along with Internet of Things are considered as backbone for the smart city evolution. IoT is concentrated more nowadays, due to the convergence of images on Information Technology and human behaviour known as Operation Technology. It is in the progressing stage with notion on cyber-physical world, where things are facilitated to satisfy feasible needs. Similarly, Internet of Medical Things is gaining attention due to the current COVID-19 situation. It has gifted numerous sensors and devices with the increased accuracy, productivity and reliability to the healthcare industry. Increasing the sensor devices in smart city, results in the handling of large amount of data. Therefore, big data is focused due to their characteristics such as volume, variety, velocity and veracity. Extraction of hidden correlations and insights from data is performed through big data analytics or big data value chain. Such concepts are integrated with Artificial Intelligence and Machine Learning technologies which are more important in collecting the real-time data collection and helps in gaining knowledge on how the smart cities and their applications in health sector evolves to adapt the conditions. The main advantage on Big Data Analytics is that it helps in commonality along with heterogeneity principles. Even though cities are digitalized, urban health is still limited to IoT devices which fetch sensor data, eliminating the inclusion of human anatomy and biological data. Integration of these two data forms will help in attaining the target of Big Data and leads to the contextualized, sustainable and resilient smart cities which renders more living factors. This chapter will focus on role of Big Data in smart health applications which plays a vital role in safeguarding the human lives.